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| author | Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> | 2018-05-11 12:51:44 -0700 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2018-05-24 16:33:35 +0300 |
| commit | 264ff016cf0672f99f98ea853dbc7e45c3527bc2 (patch) | |
| tree | 89a125b38331d0e6826b61c1a5a9262ee27c8b98 /drivers/gpu/drm/i915/intel_psr.c | |
| parent | 1e8b251ebcbbfc6bfa826bca4d91a8e1bcad2e5f (diff) | |
| download | linux-stable-264ff016cf0672f99f98ea853dbc7e45c3527bc2.tar.gz linux-stable-264ff016cf0672f99f98ea853dbc7e45c3527bc2.tar.bz2 linux-stable-264ff016cf0672f99f98ea853dbc7e45c3527bc2.zip | |
drm/i915/psr: Fall back to max. synchronization latency if DPCD read fails
Noticed that we assume the best case of 0 latency when the DPCD read
fails, reasonable pessimism is safer.
eDP spec does say that if latency is greater than 8, the panel
supplier needs to provide it. I didn't see anything specific in the VBT
for this, so let's go with 8 frames as a fallback.
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180511195145.3829-5-dhinakaran.pandiyan@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_psr.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_psr.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c index 4f34abcacacf..09f5962a19aa 100644 --- a/drivers/gpu/drm/i915/intel_psr.c +++ b/drivers/gpu/drm/i915/intel_psr.c @@ -219,13 +219,13 @@ static bool intel_dp_get_alpm_status(struct intel_dp *intel_dp) static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp) { - u8 val = 0; + u8 val = 8; /* assume the worst if we can't read the value */ if (drm_dp_dpcd_readb(&intel_dp->aux, DP_SYNCHRONIZATION_LATENCY_IN_SINK, &val) == 1) val &= DP_MAX_RESYNC_FRAME_COUNT_MASK; else - DRM_ERROR("Unable to get sink synchronization latency\n"); + DRM_DEBUG_KMS("Unable to get sink synchronization latency, assuming 8 frames\n"); return val; } |